1. Field of the Invention
The present invention relates to equipment frames and more particularly to an electrical equipment frame providing access to electrical component assemblies arranged for natural convection cooling by a slide out and hinge down arrangement.
2. Background Art
Electrical equipment frames are well known to those skilled in the art. U.S. Pat. No. 3,730,264 issued May 1, 1973, to Krylow, et al., teaches a heat exchanger for use with electronic circuitry mounted in frames. Cooling of the electronic circuitry is effected by mounting the circuitry on cards within card files which are positioned in a frame between V-shaped air deflecting plates. Cooling air enters the frame below each card file near its center and travels upward past each card, cooling components mounted thereon. The air then continues out the top of the card file and is deflected toward the ends of the card file by the V-shaped air deflecting plate. While operating generally satisfactorily, this system requires the allocation of space between each card file for use as air inlet and exhaust ducts thereby reducing the quantity of electronic circuitry which may be packaged within a frame.
German Pat. No. 1,263,119 issued Mar. 14, 1968, to Thom, et al. teaches packaging of telephone central office equipment between vertically oriented adjoining supports having, along their length, guides or resilient members arranged to accept low profile electrical or electronic assemblies. The supports or guide elements supporting a particular electronic assembly between two uprights are vertically offset so as to slant the card to the left or to the right when viewed from the front of the frame. The direction of slant is alternated in adjacent frames so as to provide intake and exhaust columns within the vertically oriented supports. Such an arrangement, while operating generally satisfactorily, requires additional engineering effort, when frames are located, to properly position the air inlet and exhaust ducts within the frame supports.
U.S. Pat. No. 3,280,377 issued Oct. 18, 1966, to Harris, et al. teaches a rack for mounting electrical apparatus on cards within card files which are inclined to the horizontal when the equipment is in use. Side panels of the rack cooperate with shelves which support the card files to form a plurality of inclined cooling ducts having the card files mounted centrally therein. Cooling air enters each card file at the back of each cooling duct, moves through each file, cools components mounted therein, and finally exhausts from the front of the card file upward. This arrangement requires the use of card relocation devices such as card extenders to diagnose circuitry operating within the frame.